1. Field of the Invention
This invention relates to a structure for locking provisionally and completely two workpieces such as a corrector housing and front holder.
2. Description of the Related Art
FIG. 8 shows an example of a conventional holder-equipped connector. A holder-equipped connector 51 includes a connector housing 52 of synthetic resin and a front holder 53 of synthetic resin that is inserted in the connector housing 52 from the front to form a terminal chamber 54.
The connector housing 52 internally includes a holder inserting chamber 55, a rear half 56 of the terminal chamber 54 which is successive to the inserting chamber 55 and a terminal locking lance 57 which projects into the holder inserting chamber 55. The connector housing 52 is externally provided with a locking arm 58 corresponding to a complementary female connector (not shown).
The front holder 53 has an end wall, upper and lower walls and an intermediate partition wall. A hole 59 through which a male terminal (not shown) of a complementary male connector is formed in the end wall. In the specification, a connector having a connector chamber is defined as a female connector while another connector which is to be inserted into the connector chamber is defined as a male connector.
The front holder 53 is inserted into the connector housing 52 from its front, and fixed within the holder inserting chamber 55 by a fixing means (not shown). Subsequently, a wire-equipped terminal 60 is inserted into the terminal chamber 54, and locked by a locking lance 57.
Since the connector housing 52 and front holder 53 are formed as individual bodies, a complicate shape such as the locking lance 57 within the connector can be easily formed in a large scale.
Various formats have been proposed for locking the connector housing 52 and front holder 53 to each other. FIGS. 9 and 10 show a format of a locking structure for a holder-equipped connector.
In FIG. 9, reference numeral 61 denotes a connector housing and reference numeral 62 denotes a front holder. The connector housing 61 has an open space 63. On the one inner wall thereof, a provisional locking projection 64 is formed, whereas on the other inner wall thereof, a complete locking projection 65 is formed. The provisional locking projection 64 and he complete locking projection 65 are formed in order from the entrance of the open space. The front holder 62 is equipped with a projecting arm 66 that approaches into the open space 63. The arm 66 is equipped with a provisional locking projection 67 on the one side and a complete locking projection 68 on the other side. The arm 66 has a slit-like hole (hollow portion) 69 formed at its center so that the locking projections 67 and 68 can warp inwardly.
As seen from FIG. 9, when the provisional locking projection 67 of the front holder 62 has climbed over the provisional locking projection 64, the complete locking projections 65 and 68 are brought into contact with each other so that the front holder 62 is provisionally locked to the connector housing 61. The connector housing 61 and front holder 62, while they are in the provisionally locked state, are transported to the subsequent step.
In the subsequent step, as shown in FIG. 10, the front holder 62 is completely pushed into the connector housing 61. The complete locking projection 68 climbs over the complete locking projection 65 so that the rear end of the complete locking projection 68 is brought into contact with the rear end of the complete locking projection 68, and an end face 70 on the bottom side of the front holder 62 is brought into contact with the front end face 71 of the connector housing 61. Thus, the front holder 62 is completely locked to the connector housing 61. In the specification, the direction of inserting the terminal and front holder 62 into the connector housing 61 is defined as xe2x80x9cfrontxe2x80x9d.
However, in the conventional locking structure of the holder-equipped connector, the pushing force required to secure the front holder 62 provisionally is substantially equal to that required to secure the front holder 62 completely. Owing to this, where the front holder 62 provisionally locked to the connector housing 61 is transported in e.g. an automated assembling machine, the front holder 62 may interfere with the outside so that the front holder 62 is inadvertently pushed in the connector housing 61. In this case, an operator must release the complete locking using a jig bar or the like. This is very troublesome.
It is preferred that the provisional locking can be done easily and the complete locking can be done surely with the aid of great force. However, conventionally, the complete locking force of the front holder 62 is small so that the front holder 62 is apt to be inadvertently released owing to vibration while the vehicle runs.
In addition, since the slit-like holder (hollow portion) must be formed as the center in the width direction of the arm 66 of the front holder 62, moldability of the arm is poor during resin molding of the front holder 62. This requires a complicate mold and hence increases the production cost.
In other cases than locking of the front holder 62, e.g. inserting a spacer for doubly locking a terminal in the connector or electric connection box, provisional locking means and complete locking means are required. In these cases also, the above problem occurs.
An object of this invention is to provide a structure for locking two workpieces which does not inadvertently secure completely two workpieces such as a front holder and a connector housing when they are locked to each other and can surely secure them completely with the aid of great force, and can be resin-molded easily and at low cost.
In order to attain the above object, in accordance with this invention, there is provided a structure for locking two workpieces comprising:
a first workpiece provided with a provisional locking arm and a complete locking arm which are in parallel;
a second workpiece provided with an arm receiving portion having a provisional engaging area and a complete engaging area which are to be engaged with the provisional locking arm and the complete locking arm, respectively and a pair of arm guiding portions on both sides of the arm receiving portion, the arm receiving portion being to advance in between the provisional locking arm and the complete locking arm, wherein one of the arm guiding portions is provided with a slope for slidably supporting a tip of the complete locking arm when the complete locking arm climbs over the complete engaging portion.
In the above configuration, the provisional locking arm is first engaged with the provisional engaging area of the arm receiving portion so that both workpieces are provisionally locked to each other. Next, as the first and/or the second workpiece are pushed in a combining direction, the complete locking arm warps outwardly while the complete locking arm climbs over the complete engaging area of the arm receiving portions and the outer area at the tip of the complete locking arm is brought into contact with the slope of the arm guiding portion so that the complete locking arm is supported in the sloped state on both ends. This increases the force required to warp the complete locking arm so that greater force is required for the complete locking than for he provisional locking. Thus, inadvertent shift from the provisional locking to the complete locking can be prevented. The complete locking arm climbs over the complete engaging area so that the former is engaged with the latter. Accordingly, both workpieces are completely locked to each other. When the complete locking is released, the outer area at the tip of the complete locking arm is in contact with the slope of the arm guiding portion so that the complete locking arm is supported on both ends. Therefore, greater force is required to release the complete locking than to release the provisional locking. Thus, inadvertent release of the complete locking can be prevented. Further, the pair of locking arms advance or retreat along the arm receiving portion and the arm guiding portions on the both sides thereof so that the pair of locking arms can be accurately positioned. This permits the provisional locking force and the complete locking force to be accurately specified.
In a preferred embodiment of this invention, the provisional locking arm has a provisional locking area at its tip, the complete locking arm has a complete locking area at its middle position in the longitudinal direction, the arm receiving portion has the provisional engaging area at its tip and the complete engaging area behind the provisional engaging area.
In the above configuration, when the provisional locking area of the provisional locking arm climbs over the provisional engaging area so as to be engaged with it, the complete locking area of the complete locking arm is brought into contact with the area of the arm receiving portion. This surely gives the provisional locked state with no backlash.
In a preferred embodiment, the provisional locking arm and the arm guiding portion have releasing slopes at their tips, respectively.
In the above configuration, when the provisional locking area of the provisional locking arm climbs over the provisional engaging area of the arm receiving portion so that the provisional locking arm warps outwardly, the slope of the outer area at the tip of the provisional locking arm passes smoothly along the slope of the inner area at the tip of the other arm guiding portion. Therefore, the provisional locking can be easily done with small force.
In a preferred embodiment of this invention, the provisional locking area and the complete locking area are formed as projections.
This configuration surely realizes the engagement between the provisional locking area and provisional engaging area in the provisional locking and the contact between the complete locking area and the complete engaging area. In addition, in the complete locking, the provisional locking portion smoothly moves straight along the arm receiving portion so that the complete locking area is surely engaged with the complete engaging area.
In a preferred embodiment of this invention, the first workpiece is a connector housing and the second workpiece is a front holder which defines a terminal chamber in the connector housing.
Owing to the above configuration, since the complete locking of the front holder to the connector housing is performed with greater force than the provisional locking thereof, the inadvertent pushing (complete locking) of the front holder and release thereof can be prevented.
The above and other objects and features of this invention will be more apparent from the following description taken in conjunction with the accompanying drawings.